This is America, where for 200 years we’ve been rolling up our sleeves puttin’ in a hard day’s work and just getting things done. And Caterpillar’s proud to have been there each step of the way. Where some see obstacles, we see opportunities. Where others say it can’t be done, we step up and say, ‘Watch us.’ It’s this genuine American spirit that helped turn Caterpillar into the company that helped move the earth and build the roads that helped build the country that changed the world.

Heck, Caterpillar doesn’t just play well in Peoria—it is headquartered there, in a city that is “synonymous with a Main Street all-American city,” where the company provides its workers with a “truly American lifetime experience,” as another pro-Caterpillar ad puts it.* (No mention in that ad that Caterpillar's CEO recently threatened to move operations out of Illinois over a state tax increase.) Caterpillar is so proudly American that when it decided to move jobs from a plant in Ontario where unionized workers were fighting pay cuts to a lower-wage location, it moved them not to Mexico but to Muncie, Indiana, where the non-union workers are making far less than their Canadian counterparts were.

The patriotic rhapsody about the company has swept up even President Obama, who declared during a 2009 visit to its plant in East Peoria: “You can measure America's bottom line by looking at Caterpillar's bottom line.”

Caterpillar, the big American maker of heavy construction and mining equipment, used a subsidiary in Switzerland to avoid paying $2.4 billion of income taxes over 13 years, according to a Senate investigative report released on Monday.

The report said Caterpillar had paid $55 million to its tax consultant and audit firm, PricewaterhouseCoopers, for helping it transfer $8 billion of profits to the Swiss subsidiary from 1999 to 2012. The transfers had no economic substance and were made solely to take advantage of the lower tax rate Caterpillar negotiated with Switzerland, according to Senator Carl Levin, chairman of the Senate Permanent Subcommittee on Investigations.

“It wasn’t a real business transaction,” said Mr. Levin, the Michigan Democrat who will lead a subcommittee hearing on the findings on Tuesday. “It was a tax deal, pure and simple, to shift profits between related parties.”

The tax-avoidance activity appears to have been controversial even within Caterpillar, with one executive disparaging it as “the pink elephant” that was “worth a billion dollars on the balance sheet,” the report said. But it also had a powerful effect on the bottom line. In 2010, Caterpillar’s finance department calculated that working through Switzerland had helped the company reduce its effective tax rate to the “lowest in the Dow 30.”

In other words, to put it in Obama’s terms: The higher Caterpillar’s bottom line, the lower America’s. By $2.4 billion, to be precise.

It’s easy to become inured to these tales of massive tax avoidance—each one that appears seems to lessen the p.r. hit for the next one: after all, if everyone’s doing it, what’s the big deal? But what makes these reports worth actually dwelling on—and holding hearings on, as Levin is doing today—is that they remind us that everyone is not doing it, or at least not to the same degree. Just because we all test the speed limit doesn’t mean it’s OK to go 85 mph down a narrow residential street, and just because companies seek preferential treatment in a messy corporate tax code doesn’t mean it’s OK for Apple to go to such great lengths to avoid taxes that, in Levin's words, it attained the "holy grail of tax avoidance," creating a network of "offshore entities holding tens of billions of dollars while claiming to be tax resident nowhere.” This is why some conscientious Caterpillar employees had misgivings about the scale of the company’s Swiss gambit (shifting billions in profit from the company’s parts business to a country where that business has only 65 employees and not a single warehouse) and it’s why even the PricewaterhouseCoopers accountants who pocketed $55 million to come up with the scheme felt a smidgen of discomfort, which one of them—managing director Steven Williams—dismissed in 2008 by e-mailing:

What the heck, we’ll all be retired when this audit comes up on audit. [Edward] Bodnam and [C]hris Dunn will have to solve it. Baby boomers have their fun, and leave it to the kids to pay for it.

Well, then. Glad to see that the Enron scandal had such an edifying effect on the ethics of the country’s big auditing firms!

There is, of course, a systemic solution to these shenanigans: comprehensive tax reform to simplify the code and give companies like Apple, Caterpillar and PwC fewer excuses to engage in such brazen avoidance. The bipartisan duo of Senate Finance Committee Chairman Max Baucus and House Ways and Means Chairman Dave Camp spent much of the past couple years working on a big reform proposal, but there so little appetite for it on Capitol Hill, and so much opposition looming among the tax lobbyists of Gucci Gulch, that Baucus bailed to become the ambassador to China, leaving Camp to release his own plan, which the wolves of Wall Street promptly devoured. Just yesterday, Camp announced that he is retiring—the very day that we learned again just how necessary tax reform really is.

As that great Swiss heavy-equipment manufacturer Caterpillar says: Whatever happened to “rolling up our sleeves puttin’ in a hard day’s work and just getting things done?” Because until we do that on tax reform, the “great American spirit” is apparently going to keep “seeking opportunities where others see obstacles,” and spiriting away our nation's tax revenue to Geneva.